Method for Measuring Air Efficiency and Efficacy in a Combine Harvester

ABSTRACT

The airflow through a harvesting machine is adjusted by calculating a G-factor at a first point on an upper chaffer to determine if it is greater than 1+n, where n represents a desired factor. A blower is adjusted to reduce an airstream if the G-factor is greater than 1+n. A MOG factor is calculated if the G-factor is less than 1+n. The blower is adjusted to increase the airstream if the MOG-factor is less than 1+x, where x represents a desired factor. A MOG-factor is calculated at a second point if the MOG-factor at said the point is greater than 1+x and the blower is adjusted to reduce the airstream if the MOG-factor at the second point is greater than 1+y, where y represents a desired factor or adjusted to increase the airstream if the MOG-factor at the second point is less than 1+y.

RELATED APPLICATION

Under provisions of 35 U.S.C. §119(e), Applicants claim the benefit ofU.S. Provisional Application No. 61/577,369 filed Dec. 19, 2010, whichis incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates to threshing and cleaning systems for combineharvesters, and more particularly, to method for managing the airflow ofa blower mechanism through the threshing and cleaning systems of thecombine harvester.

2. Description of Related Art

Combine harvesters have a threshing mechanism for threshing theharvested crop and a cleaning system used to remove chaff and otherresidue from the threshed crop. In one example, a rotor cooperates withconcaves to thresh the harvested material, and initial separation occursas grain and smaller residue are pushed through the grated concaves bycentrifugal force to the cleaning system. Large residue pieces such asstalks and stems continue to move rearwardly and are eventuallydischarged out the rear end of the rotor assembly where it is acted uponby a chopper or spreader and deposited on the ground.

Within the cleaning system, oscillating sieve assemblies in conjunctionwith air flow remove the chaff from the threshed grain, which gravitatesthrough the chaffer and sieve assembly to an oscillating clean grainpan. The clean grain pan, in turn, directs the clean grain to adischarge auger that elevates the grain to an onboard storage bin. Asecond oscillating pan directs materials other than grain over the edgeof the bottom sieve assembly to a different discharge outlet forrecirculation back through the threshing, separating and cleaningapparatus to extract the previously unthreshed grain.

A blower may be used to produce an airstream that entrains the lighternon-grain particles and carries them out the rear of the harvester.However, it can be challenging to control the airflow from the blower toget an even distribution of air across both the threshing mechanism andthe cleaning system.

SUMMARY OF THE INVENTION

In an example embodiment, the invention is directed to a method ofmanaging the airflow of a blower mechanism through the threshing andcleaning systems of a combine harvesting machine. The method includescalculating a G factor at a first point on an upper chaffer that is justunderneath the forward edge of a grain pan to determine if the G factorat said first point is greater than 1+n, where n represents a desiredfactor. The method includes adjusting the blower mechanism to reduce anairstream, thereby causing a reduction in the rearward movement of grainif the G factor at said first point is greater than 1+n. The method alsoincludes calculating a MOG factor at said first point if the G factorcalculated at said point is less than 1+n. The blower mechanism isadjusted to increase the airstream so as to entrain more MOG if the MOGfactor at said first point is less than 1+x, where x represents adesired factor. The method also includes calculating a MOG factor at asecond point if the MOG factor at said first point is greater than 1+xand adjusting the blower to reduce the airstream if it is determined theMOG factor at said second point is greater than 1+y, where y representsa desired factor or adjusting the blower to increase the airstream if itis determined the MOG factor at said second point is less than 1+y.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other features of this invention will becomemore apparent and the invention itself will be better understood byreference to the following description of embodiments of the inventiontaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic side elevational view of a combine harvester withparts broken away to reveal internal details of the feeding, threshing,separating and cleaning portions of the machine;

FIG. 2 is a block diagram illustrating a method of measuring andadjusting air flow through the combine harvester of FIG. 1 according toone embodiment of the invention; and

FIG. 3 is a graph representing grain and MOG efficiencies of thecleaning apparatus of the combine harvester.

Corresponding reference characters indicate corresponding partsthroughout the views of the drawings.

DESCRIPTION OF EXAMPLE EMBODIMENTS

The present invention is susceptible of embodiment in many differentforms. While the drawings illustrate and the specification describescertain preferred embodiments of the invention, it is to be understoodthat such disclosure is by way of example only. There is no intent tolimit the principles of the present invention to the particulardisclosed embodiments. References hereinafter made to certaindirections, such as, for example, “front”, “rear”, “left” and “right”,are made as viewed from the side of the combine.

FIG. 1 schematically illustrates one type of combine harvester 10 towhich the present invention relates. Although the harvester 10 chosenfor purposes of illustration is a so-called axial rotary combine inwhich the threshing mechanism comprises a rotor disposed axially of themachine with respect to its fore-and-aft axis, many other types ofthreshing and separating mechanisms are currently in commercial use andit is not intended that the principles of the present invention belimited to any one particular type of threshing and separatingmechanism.

In relevant part, harvester 10 has a feed housing 12 that receivesharvested materials from a suitable header (not shown) and advances suchmaterials upwardly and rearwardly via a conveyor 14 toward a beater 16rotating in a counterclockwise direction viewing FIG. 1. Beater 16impels the harvested materials upwardly and rearwardly into a receivinghousing 18. Housing 18 contains the front end of a threshing mechanism,broadly denoted by the numeral 20. In the illustrated embodiment, thethreshing mechanism 20 comprises a rotor 21 with a front end having aseries of helical vanes 22 that start the materials moving rearwardly ina spiral path of travel along the outside of the rotor 21. As thematerials move rearwardly, concaves 24 cooperate with rotor 21 to threshthe materials, and initial separation occurs as grain and smallerresidue are pushed through the grated concaves region by centrifugalforce to the cleaning apparatus 26. Large residue pieces such as stalksand stems continue to move rearwardly past a separating grate 27 whichallows grain to pass radially out of the rotor area to cleaningapparatus 26, but not the larger residue. Such residue eventuallydischarges out the rear end of the rotor assembly where it is acted uponby a chopper or spreader (now shown) and deposited on the ground. Oneskilled in the art will understand that other threshing and separatingmechanisms 20, such as a cylinder and concaves, may be used withoutdeparting from the scope of the invention.

Generally speaking, the threshed grain works its way downwardly throughthe machine as it is acted upon by the cleaning apparatus 26 and ablower 28. The blower 28 has a blower housing 29 which contains arotatable impeller 30 configured to generate a high-velocity stream ofair. The light chaff particles (MOG) become airborne by the rearwardlydirected airstream generated by the blower 28 and are discharged out therear of the machine. Clean grain ultimately finds its way to a dischargeauger 31 leading to an elevator that conveys the clean grain up to astorage tank 33 at the top of the machine. Tailings, consisting of somegrain along with the other particles of residue, find their way to atailings return auger 32 which then elevates the tailings via means notillustrated for recirculation back through the threshing, separating andcleaning areas to further separate grain from such residue.

The combine harvester 10 includes as part of its cleaning apparatus 26an upper oscillating pan 34 that delivers materials received fromconcaves 24 and grate 27 generally downwardly and forwardly. Thosematerials from pan 34 land on an upper oscillating upper chaffer 36. Theupper chaffer 36 allows grain to pass downwardly through openings in theupper chaffer 36 while larger particles are impelled generally upwardlyand rearwardly until being discharged off the rear end of the upperchaffer 36 and out the back of the combine harvester 10 to the ground. Afiner oscillating lower sieve 38 receives the grain and residue that haspassed through the upper chaffer 36 and performs essentially the sametype of classifying function as upper chaffer 36. The smaller kernels ofgrain fall through the lower sieve 38 and onto an oscillating grain pan40, which delivers the grain into the clean grain auger 30. The largertailings particles unable to penetrate lower sieve 38 travel off therear discharge end of lower sieve 38 and drop to a tailings return pan42 that feeds such materials to the tailings return auger 32. As thekernels of grain gravitate through upper and lower sieves 36 and 38, theairstream from fan 28 entrains the lighter MOG particles and carriesthem toward the rear of the harvester 10.

According to the invention, the harvester 10 contains blowereffectiveness measuring apparatus 50 used to measure the effectivenessof the airstream from the blower 28 at separating MOG from grain.Desirably, the airstream is strong enough to entrain the MOG and push ittoward the rear of the cleaning apparatus 26 without causing grain to belost out the rear of the cleaning apparatus 26. If the airstream fromthe blower 28 is not strong enough, MOG remains near the forward part ofthe upper chaffer 36. If the airstream is too strong, grain is lost outthe back of the cleaning apparatus 26 and power consumption of theharvester 10 is higher than necessary as the blower is drawing morepower than necessary. The blower effectiveness measuring apparatus 50 isused to adjust operating parameters of the blower 28 to improve theefficiency and effectiveness of the cleaning apparatus 26. Parameters ofthe blower 28, such as motor speed and position of louvers that directthe air stream, may be adjusted based on information from the blowereffectiveness measuring apparatus 50.

The blower effectiveness measuring apparatus 50 contains at least onecollection device 52 used to collect samples of the grain and MOG in thespace between the concaves 24 and separating grates 27 and the upperchaffer 36. The collection device 52 is configured to collect samplesfrom a point P₀ near the front of the upper chaffer 36 rearward to pointP₁ underneath the forward edge of the upper oscillating pan 34, andcontinuing rearward to a point P₂ near the rear of the upper chaffer 36.It is understood that the collection device 52 may be configured tocollect samples at many additional points between the labeled points P₀and P₂. The collection device 52 may include a collection tube 54 with aplurality of openings located between the point P₀ and P₂, or the tubemay be positioned on a slide so that samples can be taken along thelength of the upper chaffer 36 between points P₀ and P₂ using soundengineering judgment. The collection device 52 is desirably configuredto collect grain and MOG at the sample site for a specified duration oftime. In one embodiment, the collection tube has a door that may beselectively opened and closed for the desired amount of time to collectthe grain and MOG sample. A plurality of collection devices 52 may beused to collect samples at different points across the width of thecleaning apparatus 26. The grain and MOG collected in the samplecollected by the collection device 52 are delivered to a counting device58 that measures the amount of grain and the amount of MOG in thesample. Desirably, the counting device 58 is located outside thecleaning apparatus 26.

The measurements from the counting device 58 are used to measure theefficiency and efficacy of the airstream from the blower 28. A computermay be used to analyze the measurements from the counting device andgenerate a signal to control the blower 28 or the measurements mayanalyzed by a human operator and the blower 28 may be manually adjusted.In one embodiment, a grain effectiveness factor (hereinafter G factor)is calculated. The G factor is a ratio of the amount of grain collectedin a sample at a selected point (i.e., P₁, P₂, etc.) with the blower 28operating at a specified speed or condition to be tested and the amountof grain in a baseline sample at the selected point with the blower 28providing no air or a minimal amount of air. The G factor is calculatedusing the formula of Equation 1:

$\begin{matrix}{{G\mspace{14mu} {factor}} = \frac{{Grain}\mspace{14mu} {in}\mspace{14mu} {sample}\mspace{14mu} {for}\mspace{14mu} {blower}\mspace{14mu} {condition}}{{Grain}\mspace{14mu} {in}\mspace{14mu} {baseline}\mspace{14mu} {sample}}} & \left( {{EQ}.\mspace{14mu} 1} \right)\end{matrix}$

Similarly, the analysis device calculates a MOG effectiveness factor(hereinafter MOG factor). The MOG factor is a ratio of the amount of MOGcollected in a sample at a selected point (i.e., P1, P2, etc.) with theblower 28 operating at a specified speed or condition to be tested andthe amount of MOG in a baseline sample at the selected point with theblower 28 providing no air or a minimal amount of air. The MOG factor iscalculated using the formula of Equation 2:

${M\; O\; G\mspace{14mu} {factor}} = \frac{M\; O\; G\mspace{14mu} {in}\mspace{14mu} {sample}\mspace{14mu} {for}\mspace{14mu} {blower}\mspace{14mu} {condition}}{M\; O\; G\mspace{14mu} {in}\mspace{14mu} {baseline}\mspace{14mu} {sample}}$

Turning now to the embodiment illustrated in the flowchart shown in FIG.2, in a first step 60, the G factor is calculated at P1. Point P1 is apoint on the upper chaffer 36 that is just underneath the forward edgeof the grain pan 34. Grain drops over the forward edge of the grain pan34, so grain in the space between the upper chaffer 36 and the grain pan34 rearward of point P1 is substantially the result of grain beingentrained in the airstream from the blower 28. At 61, it is determinedif the G factor at P1 is greater than 1+n, where n represents a desiredfactor. At step 62, if the G factor at P1 is greater than 1+n, then theblower is adjusted to reduce the fan speed or alter other blowerparameters to cause a reduction in the rearward movement of grain. Atstep 64 if the G factor at P1 is less than 1+n, then the MOG factor iscalculated at P1. At 66, it is determined if the MOG factor at P1 isless than 1+x, where x represents a desired factor. At 68, if the MOGfactor at P1 is less than 1+x, then the blower 28 is adjusted toincrease the airstream so as to entrain more MOG. At 70, if the MOGfactor at P1 is greater than 1+x, then the MOG factor at P2 iscalculated. At 72, it is determined if the MOG factor at P2 is greaterthan 1+y, where y represents a desired factor. At 74, if the MOG factorat P2 is greater than 1+y, the blower is adjusted to reduce theairstream. At 76 if the MOG factor at P2 is less than 1+y, then theblower is adjusted to increase the airstream.

The blower effectiveness measuring apparatus 50 may be used duringinitial testing of harvester 10 to determine suitable speeds oroperating conditions for the blower 28 for general field or grainconditions, or the apparatus may be used periodically or evencontinuously during harvesting operations to monitor the effectivenessof the cleaning system 26 and provide periodic or continuous adjustmentsto the blower 28 to maximize blower effectiveness and efficiency.

In another embodiment, the blower effectiveness measuring apparatus 50calculates a grain efficiency reading. The grain efficiency iscalculated by summing the amount of grain collected by the collectiondevice 52 at points between P0 and P2 and comparing to the amount ofgrain collected in the baseline samples with no blower air. In oneembodiment, the grain efficiency is calculated using the formula inEquation 3:

$\begin{matrix}{{{Grain}\mspace{14mu} {Efficiency}} = \frac{\Sigma \mspace{14mu} {Amount}\mspace{14mu} {Grain}\mspace{14mu} \left( {{With}\mspace{14mu} {Air}} \right)}{\Sigma \mspace{14mu} {Amount}\mspace{14mu} {Grain}\mspace{14mu} \left( {{No}\mspace{14mu} {Air}} \right)}} & \left( {{EQ}.\mspace{14mu} 3} \right)\end{matrix}$

The MOG efficiency is calculated by summing the amount of MOG collectedby the collection device 52 at points between P0 and P2 and comparing tothe amount of grain collected in the baseline samples with no blowerair. In one embodiment, the MOG efficiency is calculated using theformula in Equation 4.

$\begin{matrix}{{M\; O\; G\mspace{14mu} {Efficiency}} = {1 - \frac{\Sigma \mspace{14mu} {Amount}\mspace{14mu} M\; O\; G\mspace{14mu} \left( {{With}\mspace{14mu} {Air}} \right)}{\Sigma \mspace{14mu} {Amount}\mspace{14mu} M\; O\; G\mspace{14mu} \left( {{No}\mspace{14mu} {Air}} \right)}}} & \left( {{EQ}.\mspace{14mu} 4} \right)\end{matrix}$

The Grain efficiency and the MOG efficiency can be plotted as shown inFIG. 3

The foregoing has broadly outlined some of the more pertinent aspectsand features of the present invention. These should be construed to bemerely illustrative of some of the more prominent features andapplications of the invention. Other beneficial results can be obtainedby applying the disclosed information in a different manner or bymodifying the disclosed embodiments. Accordingly, other aspects and amore comprehensive understanding of the invention may be obtained byreferring to the detailed description of the exemplary embodiments takenin conjunction with the accompanying drawings, in addition to the scopeof the invention defined by the claims.

What is claimed is:
 1. A method of managing the airflow of a blowermechanism through the threshing and cleaning systems of a combineharvesting machine, the method comprising: calculating a G factor at afirst point on an upper chaffer that is just underneath the forward edgeof a grain pan to determine if the G factor at said first point isgreater than 1+n, where n represents a desired factor; adjusting theblower mechanism to cause a reduction in the rearward movement of grainif the G factor at said point is greater than 1+n; calculating a MOGfactor is calculated at said first point if the G factor calculated atsaid point is less than 1+n; adjusting the blower mechanism to increasethe airstream so as to entrain more MOG if the MOG factor at said firstpoint is less than 1+x, where x represents a desired factor; calculatinga MOG factor at a second point if the MOG factor at said first point isgreater than 1+x; adjusting the blower to reduce the airstream if it isdetermined the MOG factor at said second point is greater than 1+y,where y represents a desired factor; and adjusting the blower toincrease the airstream if it is determined the MOG factor at said secondpoint is less than 1+y.
 2. The method of claim 1 wherein adjusting theblower mechanism comprises reducing the speed of the blower.